Various types of embedded devices include a main memory portion, which holds image frames. The image frames held by the frame buffer in the main memory are sent to a display via an image display processor chip. The image display processor chip may include a mechanism to manipulate the positions of pixels within the image before the image is sent to the display. For example, the image may be rotated. This may be done by manipulating the pixels, i.e., moving the pixels, and storing the resulting manipulated image in a buffer within the main memory before sending the manipulated pixels to the display. Alternatively, or in addition, the resulting manipulated image may be stored within a buffer that is part of the display processor chip.
Embedded systems, for example, mobile phones, have limited memory resources. A given embedded system may have a main memory and a system bus, both of which are shared by different hardware entities, including an image processing chip. Meanwhile, the embedded system image processing chip may require large amounts of bandwidth of the main memory via the system bus.
Memory bandwidth demands like this can result in a memory access bottleneck, which could delay the operation of the video processing chip as well as other hardware entities that use the same main memory and system bus.
To reduce this bottleneck, on-chip memory may be provided within the image processing chip, and the image processing chip may place the manipulated image in this on-chip memory. However, increasing the amount of memory within the image processing chip consumes the resources of the chip, possibly also increasing the cost of the chip.